Mystic — Mystic Aquarium announced Wednesday that two African penguin chicks have hatched, bringing the aquarium's collection of the endangered birds to 28.

The chicks hatched Feb. 1 and 10 and currently weigh 696 grams and 281 grams, respectively.

Aquarium spokeswoman Erin Merz said that the chicks will be named when they are fully fledged. The aquarium names its penguins after the color of the identifying beads they wear. One of the chick's mother, for instance, is called "Red-Blue."

The birds' genders will be determined by a DNA test when they are about six months old.

Merz said that during the first 40 days of their lives, the chicks stay warm under their parents because they cannot maintain their body heat.